The present invention relates generally to a support device for office furniture, such as desks, tables or panels, and in particular, to an adjustable support device permitting level and plumb adjustments of the furniture.
In supporting an object, such as a desk or table, it is important that the object's work surface be maintained level and plumb so that items do not roll or slide on the work surface. In addition, the appearance of uneven and non-level office furniture can detract from the aesthetics, especially when such items are incorporated into a system of office furniture. Naturally, when a support surface, typically a floor, is rippled or not level, it can be difficult to obtain a level work surface.
Another leveling problem is encountered with C-shaped desks or furniture having a surface cantilevered outwardly from a pair of support legs. If the work surface is loaded down with various heavy objects and equipment, the free edge of the surface can deflect downward, thereby giving an unsatisfactory appearance when used in a system of office furniture.
In general, individual pieces of office furniture are supported by a plurality of support legs that engage the floor. For example, a typical desk may be supported by four legs, three legs, two legs or even one leg. In particular, two-legged C-shaped desks typically have elongated feet extending forwardly from the legs in order to provide structural stability, and to prevent tipping of the object being supported. Because the legs on a C-shaped desk are positioned toward the rear of the worksurface, the C-shaped configuration provides space for uninhibited knee movement and clearance when moving between adjacent worksurfaces.
When a desk is supported by three or more legs, it is well known in the art to use a leveling screw in each leg so as to provide the work surface with height adjustment and leveling capabilities. However, such leveling screws can be unacceptable for some two-legged objects. Because leveling screws typically permit movement in only the vertical direction, a piece of furniture incorporating such a design usually lacks any angular adjustment. In essence, the object being supported can be leveled in a side-to-side manner about an axis perpendicular to the plane formed by the legs, but cannot be leveled in a front-to-rear direction about an axis interconnecting the two legs.
To counter this leveling problem, it is known in the art to provide shims or leveling screws under one or both ends of the support feet. The shims can be unsightly, however, and may not be secured to the support leg, thereby making the system inherently unstable due to its susceptibility to jarring. Moreover, leveling devices or shims which raise an end of the support foot off the floor, or are contained within an end of the foot, can present a tripping hazard and interfere with a user's feet. This problem can be exacerbated in C-shaped desks, where it may be desirable to minimize the height of the foot in order to provide minimal obstruction to the user's feet as the user moves between adjacent worksurfaces.
Other types of leveling and plumbing designs, which overcome the shortcomings of the simple shim adjustment, typically require tedious manipulation, can be expensive to manufacture or can be difficult to install.
In an effort to overcome some of these shortcomings, U.S. Pat. No. 4,135,690, issued to Clarke et al., discloses a supporting foot member extending laterally in both directions from the support leg. The supporting foot is rotatably attached to the support leg by employing two friction plates. When loosened, the plates are allowed to rotate relative to each other in order to level the object being supported. Although such a device works satisfactorily for objects having a center of gravity overlying the support leg, such as the wall panel shown in that reference, it may be incapable of supporting large loads cantilevered off of the leg, such as a C-shaped desks. To support such a load, without allowing rotation of the support leg relative to the support foot, an enormous tension load may be required to clamp the plates together. If not installed correctly, or with the proper equipment, the proper orientation of the object being supported may be difficult to maintain.
Moreover, the device disclosed in Clarke et al. must be loosened prior to each leveling adjustment. Thus, the object being leveled is itself adjusted or manipulated to the proper position, rather than having a separate adjustment mechanism acting on the object. If the object is heavy or loaded with equipment, it can be difficult to move to the proper orientation while simultaneously engaging the locking device.